This invention relates to an air cleaner for internal combustion engines, of the type in which the air in the cleaner is made to come into contact with a liquid, which is conveniently oil. These cleaners are generally mounted on power machines in which the air is very dusty and dirty, such as earth working machines, tractors, trucks and the like.
Said cleaners of known type are generally in the form of a cylindrical outer casing in which the oil is contained at the bottom, with metal mesh filter cartridges disposed in the central and upper region. The air which is fed to the cleaner through an axial cylindrical conduit inside the container flows out into the lower inner region of the container which contains the oil. Part of the solid particles in the air is retained by the oil particles which rise by suction action, while the remainder is retained by the filter cartridges. The filtered air emerges from the container above the cartridges, drawn by the engine.
The aforesaid known cleaner give rise to certain drawbacks. In this respect, there are rather high pressure drops, and the filtering efficiency at the low air throughputs is rather poor, because the oil quantity which the air is associated with under these conditions during its passage is minimal and sometimes insufficient.